Also addresses issue #1439.
I don’t like the binding iframe.on('load') events in the onclick handler, but apparently Entwine doesn't support binding on iframes.
AssetAdmin and HtmlEditorField support added
* Add arrows back to edit-all toggle button
* Don't show dimensions if the item being inserted doesn't have them.
* Set pop-up windows to be a percentage of the window height for better
use of space
* Fix broken fieldholdersmall styling within files edit
* Add placeholder if no preview
*Take out minFileSize so upload will work on Android phones
* Replaced cancel/delete button in files area
* Consolidated Image upload styles with AssetUpload styles
* Changed name of step 2 in image upload
* Made image editing hidden by default, so multiple files can be seen,
and added ability top open and close
* Tweaked styles in on page upload field (status colour and file name
width)
